SECAM
SECAM, also written SÉCAM (French pronunciation: [sekam], Séquentiel couleur à mémoire, French for "Sequential colour with memory"), is an analogue colour television system first used in France. It was one of three major colour television standards, the others being the European PAL and North American NTSC.
Development of SECAM began in 1956 by a team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson, now Technicolor). The first SECAM broadcast was made in France in 1967, making it the first such standard to go live in Europe. The system was also selected as the standard for colour in the Soviet Union, who began broadcasts shortly after the French. The standard spread from these two countries to many client states and former colonies.
SECAM remained a major standard into the 2000s. It is in the process of being phased out and replaced by DVB, the new pan-European standard for digital television.
Work on SECAM began in 1956. The technology was ready by the end of the 1950s, but this was too soon for a wide introduction. A version of SECAM for the French 819-line television standard was devised and tested, but not introduced. Following a pan-European agreement to introduce color TV only in 625 lines, France had to start the conversion by switching over to a 625-line television standard, which happened at the beginning of the 1960s with the introduction of a second network.
The first proposed system was called SECAM I in 1961, followed by other studies to improve compatibility and image quality.
These improvements were called SECAM II and SECAM III, with the latter being presented at the 1965 CCIR General Assembly in Vienna.
Further improvements were SECAM III A followed by SECAM III B, the adopted system for general use in 1967.
Soviet technicians were involved in the development of the standard, and created their own incompatible variant called NIR or SECAM IV, which was not deployed. The team was working in Moscow's Telecentrum under the direction of . The NIR designation comes from the name of the Nautchno-Issledovatelskiy Institut Radio (NIIR, rus. Научно-Исследовательский Институт Радио), a Soviet research institute involved in the studies. Two standards were developed: Non-linear NIR, in which a process analogous to gamma correction is used, and Linear NIR or SECAM IV that omits this process.
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